ts-patch-mongoose

Patch history (audit log) & events plugin for mongoose

\
\

Motivation

ts-patch-mongoose is a plugin for mongoose
\
I need to track changes of mongoose models and save them as patch history (audit log) in separate collection. Changes must also emit events that I can subscribe to and react in other parts of my application. I also want to omit some fields from patch history.

Supports and tested with

``json
{
"node": "18.x || 20.x || 22.x",
"mongoose": ">=6.6.x || 7.x || 8.x",
}
`

Features

- Track changes in mongoose models
- Save changes in a separate collection as a patch history
- Emit events when a model is created, updated or deleted
- Omit fields that you don't want to track in patch history
- Subscribe to one/many types of event
- Use events or patch history or both
- Supports ESM and CommonJS

Installation

- Locally inside your project

`bash
npm install ts-patch-mongoose
pnpm add ts-patch-mongoose
yarn add ts-patch-mongoose
bun add ts-patch-mongoose
`

- This plugin requires mongoose >=6.6.x || 7.x || 8.x to be installed as a peer dependency

`bash


For latest mongoose 6

npm install mongoose@6
pnpm add mongoose@6
yarn add mongoose@6
bun add mongoose@6

For latest mongoose 7

npm install mongoose@7
pnpm add mongoose@7
yarn add mongoose@7
bun add mongoose@7

For latest mongoose 8

npm install mongoose@8
pnpm add mongoose@8
yarn add mongoose@8
bun add mongoose@8
`

Example

How to use it with express ts-express-tsx

Create your event constants events.ts

`typescript
export const BOOK_CREATED = 'book-created'
export const BOOK_UPDATED = 'book-updated'
export const BOOK_DELETED = 'book-deleted'
`

Create your type Book in types.ts

`typescript
import type { Types } from 'mongoose'

export type Book = {
title: string
description?: string
authorId: Types.ObjectId
createdAt?: Date
updatedAt?: Date
}
`

Setup your mongoose model Book.ts

`typescript
import { Schema, model } from 'mongoose'

import type { HydratedDocument, Types } from 'mongoose'
import type { Book } from '../types'

import { patchHistoryPlugin, setPatchHistoryTTL } from 'ts-patch-mongoose'
import { BOOK_CREATED, BOOK_UPDATED, BOOK_DELETED } from '../constants/events'

// You can set patch history TTL in plain english or in milliseconds as you wish.
// This will determine how long you want to keep patch history.
// You don't need to use this global config in case you want to keep patch history forever.
// Execute this method after you connected to you database somewhere in your application.
setPatchHistoryTTL('1 month')

const BookSchema = new Schema({
name: {
title: String,
required: true
},
description: {
type: String,
},
authorId: {
type: Types.ObjectId,
required: true
}
}, { timestamps: true })

BookSchema.plugin(patchHistoryPlugin, {
// Provide your event constants to plugin
eventCreated: BOOK_CREATED,
eventUpdated: BOOK_UPDATED,
eventDeleted: BOOK_DELETED,

// You can omit some properties in case you don't want to save them to patch history
omit: ['__v', 'createdAt', 'updatedAt'],

// Addition options for patchHistoryPlugin plugin
// Everything bellow is optional and just shows you what you can do:

// Code bellow is abstract example, you can use any other way to get user, reason, metadata
// These three properties will be added to patch history document automatically and give you flexibility to track who, why and when made changes to your documents
getUser: async (doc: HydratedDocument) => {
// For example: get user from http context
// You should return an object, in case you want to save user to patch history
return httpContext.get('user') as Record
},

// Reason of document (create/update/delete) like: 'Excel upload', 'Manual update', 'API call', etc.
getReason: async (doc: HydratedDocument) => {
// For example: get reason from http context, or any other place of your application
// You shout return a string, in case you want to save reason to patch history
return httpContext.get('reason') as string
},

// You can provide any information you want to save in along with patch history
getMetadata: async (doc: HydratedDocument) => {
// For example: get metadata from http context, or any other place of your application
// You should return an object, in case you want to save metadata to patch history
return httpContext.get('metadata') as Record
},

// Do something before deleting documents
// This method will be executed before deleting document or documents and always returns a nonempty array of documents
preDelete: async (docs) => {
const bookIds = docs.map((doc) => doc._id)
await SomeOtherModel.deleteMany({ bookId: { $in: bookIds } })
},

// In case you just want to track changes in your models using events below.
// And don't want to save changes to patch history collection
patchHistoryDisabled: true,
})

const Book = model('Book', BookSchema)

export default Book
`

Subscribe

You can subscribe to events using patchEventEmitter anywhere in your application handlers/BookHandler.ts

`typescript
import { patchEventEmitter } from 'ts-patch-mongoose'
import { BOOK_CREATED, BOOK_UPDATED, BOOK_DELETED } from '../constants/events'

patchEventEmitter.on(BOOK_CREATED, ({ doc }) => {
try {
console.log('Event - book created', doc)
// Do something with doc here
} catch (error) {
console.error(error)
}
})

patchEventEmitter.on(BOOK_UPDATED, ({ doc, oldDoc, patch }) => {
try {
console.log('Event - book updated', doc, oldDoc, patch)
// Do something with doc, oldDoc and patch here
} catch (error) {
console.error(error)
}
})

patchEventEmitter.on(BOOK_DELETED, ({ oldDoc }) => {
try {
console.log('Event - book deleted', oldDoc)
// Do something with doc here
} catch (error) {
console.error(error)
}
})
``

Check my other projects

- ts-migrate-mongoose - Migration framework for mongoose
- ts-cache-mongoose - Cache plugin for mongoose Queries and Aggregate (in-memory, redis)